I forgot that! Thanks, Liz. Well, there we go: another effective plot device.

The thing that winds me up sometimes is when I don't understand the internal logic. I mean, why can't Sirius come back as a ghost? You've got all these ghosts wandering around the halls of Hogwarts for comic effect - they just feel like set dressing. Why are some people ghosts and others not? Why can't Harry's parents come back as ghosts?

And with the portraits: you never really understand what's going on there. Is it some sort of afterlife? Is the person's soul contained witrhin the portrait?